Interpretive Summary: The Nitrogen Trading Tool (NTT) is an approach to assessing nitrogen losses where once the model has been calibrated and validated for a given region, it can produce an independent, quantitative assessment of the management practices at a given site. Delgado et al. (2008; 2010a) reported that with new advances in ecotechnology such as the NTT we can start to move from the older approach to cutting nitrogen losses, where some sources of nitrogen pollution can only be identified in a general way as non-point sources, to a new approach where every field that receives nitrogen inputs can be identified as a source of nitrogen losses by a model, and where nitrogen losses can potentially be cut using a targeted, site-specific approach (i.e., precision conservation) (Delgado et al., 2008; 2010a). The advances in the last few decades from the development of desktop computers in the 1980s, to the rise of the internet in the 1990s, to the extensive GIS applications in the 2000s, will move us to the elimination of non-point sources of nitrogen losses, and towards the use of computer models to quantify nitrogen losses at a given farm and at a given time (Delgado and Berry, 2008). Computer software, internet and GIS systems, a large part of the foundation of ecotechnology, have advanced greatly. Ecotechnology also joins the fields of computer software engineering and space technologies (GIS, GPS) with the fields of agronomy, biology, biogeochemistry, hydrology, physics, and chemistry to develop advances such as models that are capable of assessing N losses, and tools such as the NTT where there is even potential for farmers to trade reductions in N loss obtained from good management practices.

Technical Abstract:
The nitrogen cycle is impacted by human activities, including those that increase the use of nitrogen in agricultural systems, and this impact can be seen in effects such as increased nitrate (NO3) levels in groundwater or surface water resources, increased concentration of nitrous oxide (N2O) in the atmosphere, and increased ammonia (NH3) deposition in natural areas. Improving nitrogen management requires that management be looked at within the context of the nitrogen cycle and with an understanding of nitrogen dynamics, pathways for nitrogen losses, and how management can serve as tool to respond to the combination of site-specific factors (such as weather, crops, hydrology, and landscape) of a given field to reduce nitrogen losses. The Nitrogen Trading Tool (NTT) (Delgado et al., 2008; 2010a) is a recent advance in the development of nutrient tools that shows how new ecotechnologies can help advance environmental conservation by moving the assessment approach from one that is limited to identifying some sources of pollution as non-point sources, to an assessment approach that is site- specific and can identify points of pollution (Delgado et al., 2010a). Not only can these new ecotechnological approaches be used to assess each field and quantity the nitrogen losses, they can also be used to help increase farms’ nitrogen use efficiencies and economic returns for farmers. Additionally, this NTT approach can be used to help identify practices and strategies farmers can use to provide these additional ecosystems services (e.g., reduced nitrogen losses) that could potentially be traded as non-commodity services in future air and water quality markets.